# print(1 + 2 - 3)
# print(1 + 2 * 3)
# print(1 + 2 / 3)

# print( (67.5 + 89.0 + 12.9 + 32.2) / 4 )

# # 平均数
# avg = (67.5 + 89.0 + 12.9 + 32.2) / 4
# # 每一项减去平均值，并平方  a ** b <=>a的b次方
# total = (67.5 - avg) ** 2 + (89.0 - avg) ** 2 + (12.9 - avg) ** 2 + (32.2 - avg)** 2
# # 前面的值除以
# result = total / 3
# print(result)

# a = 10
# print(a)

# a = 20 # 修改变量的值
# print(a) # 读取变量的值

# # 创建变量
# a = 10
# b = 20
#
# # 使用变量修改a的值
# a = b
# print(a)
# print(b)

# a = 10
# print(type(a)) # 打印变量类型

# a = 0.5
# print(type(a))

# a = 'hello'
# print(type(a))

# a = 'hello'
# print(len(a)) # 计算a字符串长度

# a = 'hello'
# b = 'world'
# print(a + b) # 拼接两个字符串

# a = True
# print(type(a)) # 打印变量的类型
# b = False
# print(type(b))

# a = 10 # int类型
# print(type(a))
# a = 'hello' # str类型
# print(type(a))

# print('hello')

# a = 10
# print(a)
# b = True
# print(b)

# num = 10
# print(f'num = {num}')

# num = 0
# num = input('请输入一个整数: ')
# print(f'你输入的整数是 {num}')

# a = input('请输入第一个整数: ')
# b = input('请输入第二个整数: ')
# print(f'a + b = {a + b}')

# a = input('请输入第一个整数: ')
# b = input('请输入第二个整数: ')
# a = int(a) # 类型转换
# b = int(b)
# print(f'a + b = {a + b}')

# a = input('请输入第一个数字: ')
# b = input('请输入第二个数字: ')
# c = input('请输入第三个数字: ')
# d = input('请输入第四个数字: ')
# a = float(a)
# b = float(b)
# c = float(c)
# d = float(d)
# avg = (a + b + c + d) / 4
# print(f'平均值: {avg}')

# print(10 / 0) # 0作为除数

# print(1 / 2)

# print(7 % 2)

# print(4 ** 2) # 整数次方
# print(4 ** 0.5) # 小数次方

# print(7 // 2) # 向下取整数
# print(-7 // 2)

# a = 10
# b = 20
# print(a < b) # 为真返回True
# print(a <= b)
# print(a > b) # 为假返回False
# print(a >= b)
# print(a == b)
# print(a != b)

# a = 'hello'
# b = 'world'
# # 字符串按照字典序比较大小
# print(a < b) # 为真返回True
# print(a <= b)
# print(a > b) # 为假返回False
# print(a >= b)
# print(a == b)
# print(a != b)

# print(0.1 + 0.2 == 0.3)

# print(0.1)
# print(0.2)
# print(0.3)
# print(0.1 + 0.2)

# a = 0.1 + 0.2
# b = 0.3
# print(-0.000001 < (a - b) < 0.000001)

# a = 10
# b = 20
# c = 30
# print(a < b and b < c)
# print(a < b and b > c)
# print(a > b or b > c)
# print(a < b or b > c)
# print(not a < b)
# print(not a > b)

# print(10 > 20 and 10 / 0 == 1) # and左侧为假，后侧不执行
# print(10 < 20 or 10 / 0 == 1)  # or 左侧为真，后侧不执行

# a = b = 10
# print(a)
# print(b)

# a, b = 10, 20
# print(a)
# print(b)

# a = 10
# b = 20
# print(a,b)
# tmp = a
# a = b
# b = tmp
# print(a,b)

# a = 10
# b = 20
# print(a,b)
# a, b = b, a
# print(a,b)

a = 10
a = a + 1
print(a)
b = 10
b += 1
print(b)